Evaluation of immune responsiveness in pure-and cross-bred chickens

The immune responsiveness of Dahlem Red and Rhode Island Red (RIR-B) strains and their cross (Dahlem Red B x RIR-B) was studied using Sheep Red Blood Cells at 0, 5, 10 and 15 days post primary inoculation (ppi). Natural antibodies were present in all the genetic groups. There was no significant difference between the two pure bred groups viz; Dahlem Red and RIR-B from day 0 to day 10 titre post primary inoculation. On genetic group pooled basis, the HA titre increased sharply from day 0 (1.24) to day 5 (6.47) ppi, and then declined slowly to 2.67 at day 15. The differences between pure groups were statistically significant at day 15 only with RIR-B having higher titre. The average of two pure was significantly higher than of the cross at day 10 and 15 ppi.